Power interlocking system for railroads



Sept. 22, 1931. F. BENEDICT POWER INTERLO CKING SYSTEM FOR RAILROADS Filed July 9, 1929 hm m mm mm Q .u xn M a mm m 80 W P 9 RU H x U m k 9 0 4 0 I I hl l T m H w G v. A XU v 0 km. Q

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Patented Sept. 22, 1931 UNITED STATES FRANK BENEDICT, 0F RUTHERFORD, NEW JERSEY, ASSIGNOR T'O GENERAL RAILWAY SIGNAL COMPANY, 01 ROCHESTER, NEW YORK POWER INTERLOCKING SYSTEM FOR RAILROADS Application filed July 9, 1929. Serial No. 377,033.

This invention relates to power interlocking systems for railroads, and more particularly to a means for safeguarding the operation of a power operating switch, part1 cu 5 larly under conditions where hand operation of the switch is required.

It is sometimes necessary, either because a switch machine or one of its associated control devices is out of order, or for mainte- 0 nance or adjustment, to operate aswitch machine by hand; and it sometimes happens, when this is done, that the switch machine is accidentally or carelessly left in a position out of correspondence with its control lever.

For various reasons, which will be evident to those skilled in the art, such a condition of switch machine outof correspondence with its control lever is objectionable, and may result in an improper operation otthe switch under a train under certain conditions or combination of circumstances.

In accordance with the present invention, it is proposed to provide means such that, oncethe power has been cut off from the switchmachine and it has been operated b hand, power can not be again applied until the switch machine is moved over and locked in a position corresponding to the position of the control lever. This feature, in combina- 5' tion with an electric lever lock, track circuit controlled power control means, and other expedients for safeguardingthe power oper ation of the switch, assures safe operation or control of a power operated switch under all 5 or" the conditions and circumstances likely to be encountered in practice.

The various characteristic features of the invention, and its advantages, will be in part apparent, and in part pointed out as the de- The accompanying drawing-illustrates in a diagrammatic and conventional manner one specific embodiment of the invention, which is susceptible of consider'ablemodification or adaptation in practice, depending upon the conditions'encountered and the degree of safety desired. I

The selected embodiment of theinvention shown exemplifies the: application of the principles and functions characterizing the inven- 1, safety magnet S, and cross-protection re- I lay OP. These parts and devices are of the usual construction, and operate in the way characteristic of this dynamic indication type system as described, for example, in the patent to Howe, 1,550,611, August 18, 1925. For the purposes of this invention, the lever LV is provided with two extra pairs of contacts 6 and 7, closed in the normal andreverse indication and the full normal and reverse positions.

' The switch SW, having the usual signal 8 and detector track circuit with the track relay T, is operated in the usual way by a switch machine SM, shown conventionally, which is preferably of the construction shown and described in the patent to Howe, No. 1,466,-.

903, September 4:, 1923. This switch machine, as disclosed more in detail in said Howe patent, includes means for permitting its hand operation which comprises a socket (indicated at 9 in the accompanying drawing) to receive a hand crank (not shown), this socket being normally obstructed or partially covered by a guard plate 1O, pivoted at 11, so that the hand crank can not be inserted until this guard plate 10 is moved aside to the position partly shown in dotted lines to align a hole 10 in said guard plate with the socket 9 for the hand crank. This guard plate 10 is connected to a rod 12, carchine, as shown, for example, in the patent to Bushnell, No. 1,517,236, November 25, 1924.

As shown, these pole-changer contacts PC comprise pairs of contact springs, as 17, 5 bridged by contact blocks, as 18, these contact springs being-connected to a suitable source of current, as the transformer 19.,.and.to two wires and 21, and also interconnected, in such a way that alternating current of one instantaneous polarity is connectedto the wires 20 and 21, with the switch machine over and locked in one position, and the opposite instantaneous polarity'with the switch machine over and locked 1 1116116 other position, these wires 20 and 21 being tie-energized as soon as the switch machine is unlocked and so long as it is in an intermediate position. These. wires 20 and 21 extend to :the tower and are connected toone winding of a two element three-position alternating'current indication. relay WVP, havingaa contact ifinger 22, which'is operated to one extreme position or the other, when the switch machine is over and locked in the corresponding position and .5 which assumes an intermediate or neutral position when the switch machine is in midstroke or unlocked. I

As an additional feature of safety, I iprets er-ably make-the operation of the switch machine @dependent upon the position '01 condition of the track device vof a suitabletrain control or train stop means, for thepurpose and in the manner more fully disclosed in the application of J. J. Larkin, Ser; No. 376,555 filed July 8, 1929. in :the drawing, I have'shown conventionally a trip stop ST, having contacts 23 operated thereby and closed whenthistrip is in .the raised'or stopping position.-

vIn the tower is a two element alternating current relay LR, having two windings, 24 and 25, and closing front contacts 26and 52.7, when both of these windings are energized with alternating current. Theifrontcontacts V 2.7 of this relay LR areincluded in-lmultip'le between the battery B, or other source of'cur rent tor operating the switch machine, and the-safety magnet 18, so thatwhen the relay LR is de-energized, the supply ofcurrentto the contacts of the lever :LV and thence to the switch machine is cut off, and the switch machine can not be operated.

' The winding of the relay LR is energized by a circuit including the contacts 23 of the trip stop ST and'the front contact 28 of the detector track relay T, this circuit beingtraced as follows:starting at oneterminal of suitable'sou'rce of alternating current. designated BX, contacts 23 ofithe trip ST, wire 29, front contact 28 of the detector track relay T, wires 30 and 3.1-,winding 25 ofithe relay LR, to the other terminal :of said source designated The-other winding 24 of :the relay LR 'has two circuits for normally energizing-it, one

a stick circuit including its front contact 26, and the other a pick-up circuit. The stick circuit for the winding 24 of the relay LR may be traced from BX through the crank contacts l4-16, wire 32, front contact 26 of relay LR, wires 33 and 34, winding 24 to The-Lother pick-up circuit for the winding 24 of the relay LR may be traced from BX through the contact finger 22 of the relay VP norma'hwire 35, in the normal positlOIlylBVGl contacts 7, wires 36 and 34, winding 24to OX, Ifthe relay WP is in the reverse position, and the'lever is also in the re verse po$ition,..-.this energizing circuit is through the contact finger 22 of the relay WPwreversed, wire 37, reverse lever contact -6., -wire38, and thence along wires 36 and 34 through the relay Winding 24 toCX.

If the trip stop ST is in its raised or stopping position and .its contacts 23 are closed, and if the detector track relay T is energized,.the magnet of the lever lock L is energized, upon closing of the latch contacts 5, in multiple with the winding 25 of the relay LR over wires 39 and 40, latch contact 5, wire 41, lock magnet L to CX.

Considering the operation under normal :conditions,-i f the tripstop :ST is raised and the detector track circuit is unoccupied, the electric lever lock L may be energized, so that the operator may shi fthis lever from the normal position-shown to the reverse indication position. This breaks the pick-up circuit for the winding 24 of the relay LR at the normal lever-contact 7, but this winding is maintained'energized by the stick circuit through the crank contacts 1416. The winding 25 of the relay LR is also energized under the conditions assumed, and the front contacts 27'areclosed, so that as soon as the lever L'V :is pulled to its reverse indication position, power :is applied to the switch machine to operate it in the usual way to the "reverse position.

a "the trip stop ST should not lie in its raised or stopping position, so as to stop trains attempting to passover the switch, or if the detector track circuit should be occupied,thewinding 25 of the relay LR is deenerg ized, opening the front contacts 27 of said relay and cutting off the supply of power to the switch machine. Also, the lever lock L couldnot be energized underthese conditions. Gonsequently, the switch could not be operated by power under these conditions, both because the lever LV couldnot be moved and because no current-could be supplied to the switch machine. 7

If a' tr'ain should happen to runby the sig- 'nal' 8, after the switch machine had been In this connection, it should be understood that both windings 24 and 25 of the relay LR must be energized with alternating current, suitably displaced in phase, in order to close its front contacts, as would be obvious to one skilled in the art. In the case'assumed, the switch would be stopped as soon as the train entered the detector track circuit, and perhaps the switch points might be left in midstroke or unlocked; but this condition, particularly for subways, is considered to be preferable to permitting continued operation of the switch machine after entrance of the train into the detector track circuit, on the theory that it is better to de-rail the train under such emergency conditions, rather than throw the switch under it. If desired, however, provision may be made, as shown, for example, in the patent to Howe, No. 1,550,611, August 18, 1925, so that the switch machine will complete its cycle of operation when started prior to the entrance of a train into the detector track circuit. In the special case under consideration, the brakes would of course be automatically applied by the tripstop ST, when the train entered the trackcircuit; and

in some cases this would stop the train be-' fore it reached the switch, depending of course upon the speed of the train at the time and distance between the trip ST and the points of the switch.

Considering now the feature more particularly characterizing the present invention, assume that it is necessary, for some reason,

to operatethe switch machine by hand. For

e:.:ainple, there may be some obstruction in the points which has to be removed, or a temporary interruption in the power, or some defect or misadjustment in the switch machine itself. Under these conditions, before the hand crank can be used, the guard plate 10 must be moved, and this opens the contacts 1et-16, breaking the stick circuit for the winding 24 of the relay LR. If at this time the switch machine is unlocked or in midstroke, the pole-changer contacts PC are opened and the indication relay WP is deenergizcd, so that the pick-up circuit for the winding 24 of the relay LR is also ole-energized, with the result that the front contacts 2'? of this relay open and cut oif the supply of power to the switch machine. The same thing happens as soon as the switch machine is cranked. Asan additional safeguard, to take .careof the condition where the switch machine may be over and locked in one position, and the control lever LV is in the corresponding position, the contacts 13-15, operated by the guard plate 10, are preferably provided to break the common return connection to the switch machine, upon operation of said guard plate to permit hand cranking.

after the switch machine has been cranked by hand one or more times, the crank retacts l t-15 will not re-energize the winding 2 1 of the relay LR. It is necessary to close the pick-up circuit for the winding 2% of the relay LR; and this happens only if the switch machine is over and also looked, so as to energize the relay VP, andthis position of the switch machine corresponds with the position of the lever. Consequently, after any manual manipulationof the switch, it is assured that power can not be re-applied to the switch until it is put in. a' position corre' sponding with its controlleven. y I a;

This arrangement Tavoids such improper operation of the switch as may occur, under special conditions, where the switch machine, afterhand cranking andrepair, or adjust.- ment, is left in a position out of correspondence with its control lever, and .power for some reason, is applied while a tram is approaching or passing over the switch. Such improper operation is particularly likely to occur where dependence-is placed upon an electric lever ,lock, and there is no directtrack circuit control of thelpower supplied to the switch machine. 1 1 1 It is sometimes desirable, in the case of a track circuit failure, or the like, to be able to operate the switch machine by power, as an emergency measure; and for this purpose there is shown an emergency release button ER, which is suitably protected by a seal or the like, and which may be manually moved from the position shown to applycurrent from BX through contacts 45 to wireJiG, to energize the electric lock L and the winding 25 of the relay LR,and through contacts 17 and wire 48, to energize the winding 2a of the relay LR. A circuit, including the normally closed contact 47 on the emergency release button ER, is preferably employed to control the clearing of thesignal 8, or the like, so that the emergency button ER has to be returned to its normal position, after each operation, to permit clearing of the signal and normal train movements.

The invention is applicable to other types of power inter-locking, and is'further susceptible of considerable modification and adaptation; and it should be understood that the invention is not limited to the particular construction and arrangement of parts and circuits shown and described.

WVhat I claim is a 1. In a power interlocking system, a switch machine, a lever for controlling the operation of the switch, machine,. said switch machine including means operable to per- I as unit manual manipulation thereof, a power cut-.oifkdevice rendered effective by opera tion of said :means, .and means preventing restoration of :power to the switch machine unless it is in .a position corresponding with :the position of said control lever.

. 2.. Inapower'interlocking system, a power operated switch machine, a control lever therefor, manually operable means for cutting off the power and permitting manual .operationof the switch machine, and means for restoring power :to said switch machine only if it is locked ina position corresponding to the position of its control lever.

In a power interlocking system, a power operated switch machine, a control lever therefor, means permitting hand operation otthe switch .and including a movable member which must be shifted before the machine can be operated by hand, a stick relay controlling the application of power to the switch machine and having its stick circuit broken by the movement of said member, and

' means for re-energizing said stick relay only if the switchma-chine is in a position corresponding to the position of its control lever.

4; In a ipower'interloc'kingsystem, a power-operated switch machine, a control lever therefor, means operable to cut off the supply of powerto said switch machine independently of the position of said control lever :and maintained in the operated condition until restored, and means for restoring said cutoff meanseifective only if the switch machine and its control lever are in corresponding positions.

In a power interlocking system, a power operated switch machine, a control lever therefor, a detector track relay, a power con trol relay having two windings for controlling the supply of current to said control lever,'t'l1eenergization of both of said windings being necessary to close the contacts of said relay, an energizing circuit for one of said windings controlled by said track relay, said switch machine including manually operahle crank contacts which must be opened before the switch can be operated by hand, and a circuit including said manually operable crank contacts for energizing the other winding.

-6. Ina power interlocking system, a power operated switch mac'h ine, a control lever tl'ierefor,a detector track relay, crank contacts opened to permit manual operation of: the switch machine, and means for cutting of? the supply of current to said switch ma chine if said track relay is (lo-energized or if said contacts-are opened, said means when operated by the opening of said contacts being restored to normal-only if the switch machine and its control lever are in corresponding positions. l

i '7. In a power interlocking system, a powrelay having two windings both of which must be simultaneouslyenergized with alternating current to operate the contacts of said relay, the energization of one winding of said relay being controlled by said track circuit, and an energizing circuit for the other winding of said relay closed only if the switch machine and its control lever are in corresponding positions.

8. In an interlocking system, the combination with a power operated switch machine, a: control lever therefor, a detector track circuit, and power control means for governing the application of power to said switch machine rendered effective by the occupancy said track circuit to prevent operation oi." the switch machine, said means when effective remaining in that condition until the switch machine and its control lever are in corresponding positions.

9. In an interlocking system for railroads, a power operated switch, a control lever having normal and reverse contacts, a relay energized normal or reverse if said switch is over and locked in a corresponding position, said relay being de-energized whenever the switch is unlocked or in midstroke, means for controlling the supply of current to said lever, and an energizing circuit for said means including two branches in multiple, each branch including corresponding normal and reverse contacts of said lever and said relay.

10. In an interlocking system, a power operated switch, an indication relay controlled in accordance with the positions of said switch, a control lever having normal and reverse contacts, a stick relay acting if energized to supply current to said lever, and a pickup circuit for said stick relay including corresponding normal and reverse contacts on said lever and said indication relay.

11. In a system for protecting power-operated switches, a switch machine, a control lever for governing the operation of the switch machine, means for permitting hand operation of the switch and including a movable member which must "be shifted'before the switch can be operated by hand, contacts opened by the movement of said member to its. shifted position, .a normally energized stick relay acting when de-energized to cut en"- the supply of current to the switch md chine, a stick circuit for said relay including said contacts, an indication relay controlled in accordance with the position of said switch, and a pick-up circuit for said stick relay including corresponding normal and reverse contacts of said control relay and said indication relay, whereby said stick relay is not ire-energized unless said control lever and switch machine are in corresponding positions.

12. In a system for the power operation of track switches, a switch machine, a control lever therefor, a detector track relay, a normally energized stick relay controlled by said track relay and acting when de-energized to cut ofl the supply of current to the switch machine, and a pick-up circuit for said relay closed only if said control lever and said switch machine are in corresponding positions.

13. In a system of the type described, a power-operated switch machine, a control lever at a distant point for governing the operation of said switch machine and having normal and reverse contacts respectively closed in the corresponding controlling positions of said lever, an indication relay atsaid distant point controlled in accordance with the position of said switch and having normal and reverse contacts respectively closed only if said switch is in a corresponding position, a power control device operable to prevent power operation of the switch machine and when once operated remaining in that condition until restored, and a restoring circuit for said device included in series the cor responding normal and reverse contacts of said control lever and said indication relay.

14. In a system for the power operation of a track switch, a switch machine for moving the switch, a control lever for governing the operation of said switch machine, an indication relay having a contact operated to different positions in correspondence with the position of said switch, a trackway train control device for governing train movement over the switch, means for cutting off the supply of current to said switch machine when said train control device is in its non-stopping condition, said means when once operated remaining in that condition until restored, and means for restoring said power cut-off means only if said control lever and the contact of said indication relay are in corresponding positions.

15. In a system of the character described, a switch machine, means for permitting hand operation of the switch and including a movable member which must be shifted before the switch can be operated by hand, protective means for preventing the power operation of the switch and automatically rendered eflective by the movement of said movable member to its shifted position, said protective means when once rendered eifective remaining in that condition until restored, control means for governing the operation of the switch machine, and means for restoring the said protective means only if said control means and the switch are in corresponding positions.

In testimony whereof I affix my signature.

FRANK BENEDICT. 

